A similar process is described in Russian Patent Specification No. 236,462. In the process therein described, vinyl cyclohexene is converted at a temperature of 300.degree.-400.degree. C. to ethyl benzene in the presence of a catalyst consisting of palladium or carbon with a conversion of 95% and a selectivity of 92% towards ethyl benzene. Another similar process is described in the Journal of Catalysis 50 (1977) p. 172. That process employes palladium-on-alumina catalyst with the vinyl cyclohexene being completely converted to ethyl benzene. One significant disadvantage of these processes is that the catalyst activity decreases fairly rapidly with the catalyst being practically fully deactivated after about 1-2 weeks.
The present invention however, overcomes this disadvantage by providing a process by which an alkenyl cyclohexene can be converted substantially quantitatively to the corresponding alkyl benzene with the aid of a catalyst, which even after several months of operation exhibits very little deterioration in activity.